Integrated circuit (IC) devices (e.g., chips) are typically manufactured with thousands, millions, or even billions of transistors in a single device. Proper operation of such devices can often require precise timing and or performance between various circuit sections. Unfortunately, the operation of such transistors can be subject to uncontrollable variation arising from numerous sources. Variations can arise from the manufacturing process used to fabricate the device, variations in device materials, changes in operating temperature, variations in power supply voltages, or even the age of an IC device, to name but a few.
Conventionally, IC devices are designed to try to accommodate such variations, by including extra circuits and/or higher operating voltages. Such approaches can be conceptualized as “overdesigning” a chip; as such approaches could be avoided if transistors had less variation in performance. As device features continue to shrink in size and operate at lower voltages, conventional overdesign techniques may require undesirably large amounts of device area and/or circuit power to achieve a desired circuit performance.
All of the above can present formidable limits to achieving faster and more efficient IC devices with conventional transistors and design approaches.